^Daniels, Peter T. (1996). The World's Writing Systems. Oxford University Press. p. 367. ISBN 978-0-19-507993-7. https://books.google.com/books?id=ospMAgAAQBAJ&pg=PA367
^Aronson, Howard Isaac (1990). Georgian: A Reading Grammar. Columbus, OH: Slavica Publishers. p. 18, 20. ISBN 978-0-89357-207-5. http://www.seelrc.org:8080/grammar/pdf/stand_alone_georgian.pdf